'Switching on' means 'to turn on (something) by turning or pushing a button or moving a switch, lever, etc.' Thus option A is the correct answer.
243.
He comes . . . . . . . . a car.
(A) at
(B) by
(C) with
(D) on
Solution:
When you are talking about general ways to travel, use the preposition "by". For example, you can travel by train, by car, by bus, by truck, by plane, by motorcycle, by helicopter or by boat.
244.
The most beautiful bird was flying . . . . . . . . the river.
(A) with
(B) on
(C) in
(D) across
Solution:
'Across' means 'on the other side of something, or from one side to the other of something which has sides or limits such as a city, road or river'. Hence it makes the sentence meaningful.
245.
What is happening . . . . . . . . this picture?
(A) at
(B) from
(C) of
(D) in
Solution:
'In' is used when something is within, i.e. one thing contains another. Here a particular event is within the 'picture'.
246.
William says that he aims . . . . . . . . winning at least a consolation prize.
(A) to
(B) at
(C) on
(D) for
Solution:
'At' indicates specificity of something. Here, a specific 'consolation prize' is something that William is aiming for.
247.
He came . . . . . . . . me in the market.
(A) at
(B) into
(C) across
(D) of
Solution:
'Come across' means 'meet or find someone or something by chance'. Hence it makes the sentence meaningful.
248.
It is awful to be afflicted . . . . . . . . a sense of inferiority.
(A) with
(B) by
(C) at
(D) up
Solution:
'Afflicted with' is used when the disease stays for long period of time. For example: He was afflicted with asthma, and his retirement was relieved only by the society of a few chosen friends. 'Afflicted by' is used when the disease or illness stays for a shorter period of time.
249.
Be polite . . . . . . . . your juniors.
(A) to
(B) from
(C) to
(D) against
Solution:
In the blank, preposition "to" will be used because preposition "to" is used to indicate a relationship between two things or person or to show the inclination of something on someone.
250.
His attitude . . . . . . . . his work is very negative.
(A) to
(B) in
(C) about
(D) of
Solution:
In this sentence, the preposition that appropriately fits in the blank to convey the intended meaning is "in". The complete sentence would be: "His attitude in his work is very negative." This usage of "in" indicates that the negativity is associated with his work or is reflected within his work. It's a common preposition to use when describing someone's attitude or behavior in a specific context, in this case, his work. The other options do not fit as well in the context of the sentence: Option A: to would imply a different relationship between attitude and work. Option C: about and Option D: of are less commonly used in this context. So, the correct answer is Option B: in.